World leaders attending a conference on Islam's global roles are calling on Muslim clerics and scholars to do more to denounce terrorism and its masterminds.

The gathering in Vienna of religious and political leaders is examining ways to improve contacts between the West and Muslim nations.

Iraqi President Jalal Talabani told the gathering that if terrorism is not denounced it might allow Islamic radicalism to spread. He said Islamic leaders must declare that terrorist groups are only trying to deceive their followers and do nothing but create destruction.

Afghan President Hamid Karzai warned that failure to defeat Taleban-led terrorism in his country could have wider consequences, and predicted more attacks to come. But he vowed they will not stop him from democratizing the country and further strengthening the democratic institutions.